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United States Patent Army Filed Nov. 7, 1962, Ser. No. 236,170 4 Claims. (Cl. 89-191) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to guns in which the forces developed by the discharge thereof actuate the guns operating mechanism and it relates more particularly to such guns in which the operating mechanism is actuated by a gasenergized piston.

It is one object of this invention to provide a gas system for guns whereby the discharge gases are isolated from the gas system to eliminate fouling and carbon accumulation therein.

It is another object of this invention to provide a gas system for guns whereby the case of the fired cartridge is permitted to expand to energize the air trapped between the case and the barrel chamber and the energized air is used to actuate a piston.

The specific nature of the invention as Well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectioned view of a section of a gun showing the gas system therein with a live cartridge in the barrel chamber;

FIG. 2 is a view similar to FIG. 1 but showing the cartridge discharged;

FIG. 3 is a view similar to FIG. 1 but showing a different configuration of the cartridge case and cartridge chamber; and

FIG. 4 is a similar view showing still another configuration of the cartridge case and cartridge chamber.

Shown in FIGS. 1 and 2 is a section of a gun 8 which includes an operating rod 10, a barrel 12, which receives a cartridge 14 for discharge, and a gas system 16 for energizing the operating rod responsive to discharge of the cartridge in the barrel. Gas system 16 includes a case 17 of cartridge 14, a cartridge chamber 18 formed in the rear end of the barrel, a gas cylinder 20 extending forwardly into the barrel from the rear end thereof parallel to the cartridge chamber, a piston 21 slidingly mounted in the gas cylinder for actuation against operating rod 10, and a gas port 22 which provides communication between the cartridge chamber and gas cylinder.

Case 17 is provided with a forwardly tapering body portion 26, a neck section 28, which grips a projectile 30 and is tapered slightly, and a conical section 32 which integrally connects the body portion and neck section.

Cartridge chamber 18 includes a cylindrical largediameter portion 34 which extends from the rear end of barrel 14 to an annular shoulder 36 and is arranged to receive body portion 26 and conical portion 32. A cylindrical small-diameter section 38 extends forwardly from shoulder 36. The diameter of small-diameter section 38 is slightly smaller than that of the largest diameter section of neck section 28 to produce a press fit between the neck section and an edge 39 formed at the junction of shoulder 36 and the small-diameter section. The diameter of largediameter portion 34 is slightly smaller than the largest diameter section of body portion 26 at the rear end thereof to provide a slight press fit therebetween when cartridge 14 is seated in cartridge-chamber 18. As body portion 26 is tapered forwardly from the base thereof and largediameter portion 34 is cylindrical, an annular air-chamber 40 is formed therebetween when cartridge 14 is fully received by cartridge chamber 18 for discharge. The front end of chamber 40 is closed by the snug contact of neck section 28 with edge 39 and the rear end is closed by the snug contact of large-diameter portion 34 by body portion 26 at the rear end thereof. Gas port 22 is disposed between the front end of large diameter portion 34 and the front end of gas cylinder 20.

Thus, when cartridge 14 is discharged in cartridgechamber 18, the discharge causes body portion 26 to expand into contact with large-diameter portion 34 and thereby collapse chamber 40, compressing the air therein and forcing it through gas port 22 into gas cylinder 20. The pressure of the air received by gas cylinder 20 energizes piston 21 for actuation against operating rod 10.

Shown in FIG. 3 is a cartridge-chamber 46 and a cartridge 48 having a cylindrical section 50 at the rear end to increase the area of contact between the cartridge and the cartridge-chamber thereat and thereby increase the initial seal therebetween. Also, the front end of largediameter portion 52 of cartridge-chamber 46 is countersunk at 54 so that a conical section 56 of cartridge 48 has contact therewith, when the cartridge is seated in cartridge-chamber 46, to increase the area of contact between the cartridge and cartridge-chamber at the front end and thereby the initial seal therebetween.

Shown in FIG. 4 is a cartridge-chamber 60 and a cartridge 62 having a conical case 64 with a base 66 terminated at the front end by an annular shoulder 67. Cartridge-chamber 60 is counterbored from the rear end to form an annular recess 68 for matingly receiving base 64. Body portion 70 of cartridge 62 is shorter than the corresponding large-diameter portion 72 of cartridgechamber 60 to increase the size of chamber 74 formed between cartridge 62 and cartridge-chamber 60. With the rear end of case 64 being anchored to barrel 12 by the contact of annular shoulder 67 with the front end of recess 68, the front end of the case stretches forwardly as well as outwardly to collapse chamber 74 when cartridge 62 is discharged.

From the foregoing it is clearly apparent that there is provided herein for guns a gas system which is simple in construction and in which fouling and the accumulation of carbon deposits have been eliminated as the discharge gases are isolated from the gas port and gas chamber.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In a gun having a barrel for discharge of a cartridge and a reciprocal operating rod, a gas system including a gas cylinder, a piston mounted in said gas cylinder for actuation against the operating rod when energized, an air chamber formed in the barrel so as to be isolated from the bore thereof when the cartridge is chambered in the barrel for discharge, means providing communication between said air chamber and said gas cylinder, and means for compressing the air in said gas chamber to energize said piston when the cartridge is discharged in the barrel.

2. In a gun having a barrel for discharge of a cartridge and a reciprocal operating rod, a gas system including a gas cylinder, a piston mounted in said gas cylinder for actuation against said operating rod when energized, a case of the cartridge expendable by discharge thereof, a cartridge chamber in said barrel for receiving said case, an air chamber formed in said cartridge chamber when said case is received thereby for discharge, said air chamber being collapsible to compress the air therein when said case is expended by dischar 'e of the cartridge, and means for passing the compressed air from said air chamher into said gas cylinder to energize said piston.

3. The gas system as defined in claim 2 wherein said case and said cartridge chamber are of different configuration to form said air chamber therebetween and wherein said case and said cartridge-chamber are provided with cooperating surfaces arranged to form sealing contact at the front and rear ends of said air chamber when the cartridge is fully received by said cartridge chamber.

4. The gas system as defined in claim 3 wherein a part of said air chamber is formed forwardly of said case, and

said case is provided with means for anchoring the rear end thereof to said barrel to assure a forward stretching of said case to collapse said air chamber when the cartridge is discharged.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A GUN HAVING A BARREL FOR DISCHARGE OF A CARTRIDGE AND A RECIPROCAL OPERATING ROD, A GAS SYSTEM INCLUDING A GAS CYLINDER, A PISTON MOUNTED IN SAID GAS CYLINDER FOR ACTUATION AGAINST THE OPERATING ROD WHEN ENERGIZED, AN AIR CHAMBER FORMED IN THE BARREL SO AS TO BE ISOLATED FROM THE BORE THEREOF WHEN THE CARTRIDGE IS CHAMBERED IN THE BARREL FOR DISCHARGE, MEANS PROVIDING COMMUNICATION BETWEEN SAID AIR CHAMBER AND SAID GAS CYLINDER, AND MEANS FOR COMPRESSING THE AIR IN SAID GAS CHAMBER TO ENERGIZE SAID PISTON WHEN THE CARTRIDGE IS DISCHARGED IN THE BARREL. 